Diffuse nodular lymphoid hyperplasia of the large bowel without hypogammaglobulinemia or malabsorption syndrome: a case report and literature review.

Diffuse nodular lymphoid hyperplasia (DNLH) of the intestine is an extremely rare lymphoproliferative disorder occasionally associated with non-Hodgkin lymphomas. We report an unusual case of DNLH of the entire colon, which resembled malignant lymphoma (particularly low-grade B-cell lymphoma) both on clinical and pathologic grounds. The patient was a 62-year-old Japanese woman who was found to have multiple polypoid lesions along the entire large intestine by colonoscopy. Abdominal computed tomography revealed hepatosplenomegaly and multiple mesenteric lymphadenopathy. Histologically, the lesion was characterized by numerous lymphoid follicles with active germinal centers and a diffuse infiltrate of lymphoid cells in the mucosa and submucosa. The present case appears to be an essentially benign condition bearing a resemblance, both clinically and histologically, to malignant lymphoma, and from which it can be distinguished by use of immunohistochemical or molecular analysis.